Responses to requests for public records shall be made promptly. Within five business days of receiving a public records request the department head or the department head's designee shall respond by either (1) providing the record; (2) acknowledging that the city has received the request and providing a reasonable estimate of the time the city will require to respond to the request; or (3) denying the public record request on the grounds that the records requested are exempt from public inspection under Chapter 42.56 RCW or other applicable law. Additional time required to respond to a request may be based upon the need to clarify the intent of the request, to locate and assemble the information requested, to notify third persons or agencies affected by the request, or to determine whether any of the information requested is exempt and that a denial should be made as to all or part of the request. In acknowledging receipt of a public record request that is unclear, the department responding may ask the requestor to clarify what information the requestor is seeking. If the requestor fails to clarify the request, the department need not respond to it. All denials shall be in writing and shall specify the reasons for the denial, including a statement of the specific exemption authorizing the withholding of the record and a brief explanation of how the exemption applies to the record withheld. In addition the department head may delete identifying details when it makes available or publishes any public record when there is reason to believe that disclosure of such details would be an invasion of personal privacy protected by Chapter 42.56 RCW. Any such deletion shall be accompanied by a written justification.